3 in 1 underlayment for flooring

You Ask We Answer | Flooring Underlayment Options

Hello all, today's 'You Ask We Answer' blog post ... What types of underlayment are available for me to consider when buying a floating floor and do I need to buy it? Another question we get is: "do I need underlayment for vinyl flooring with attached pad?"

The short answer to "do I need underlayment for vinyl flooring with attached pad?" is 95% off the time, no, you do not. But there are a few exceptions to this answer, so head to the end of there article for a longer form answer.

Back to the first question of do I need underlayment with a floating floor? We get this question every day in some form or another. The quick answer is YES, you need underlayment on a floating floor. It is so common for the simple reason that you can't have a floating floor without something to float it on! Underlayment is mandatory component to a floating floor installation. We have snapped a few photos for you from our warehouse and will give you the high level answer to help you prepare to make your buying decision. Follow these points and you are going to be heading in the right direction.

3 in 1 underlayment for flooring, Word of Mouth Floors Richmond BC Canada

When buying flooring underlayment ask yourself this:

1) do I need it?

2) is moisture a concern

3) is sound a concern?

4) Is my Subfloor perfect?

5) Budget

Vinyl underlayment for flooring, Word of Mouth Floors Richmond BC Canada

(1) Do I Need Flooring Underlayment?

If you are doing a floating floor installation, you must have underlayment. This means if you have a laminate click lock floor, a vinyl click lock floor, or wish to float an engineered hardwood floor, yes, you need underlayment. When do I NOT need to buy extra rolls of underlayment for my hard surface flooring purchase? When the underpad is already attached to the flooring. Many types of SPC Vinyl flooring has pad attached already, and as that type of flooring is waterproof, therefore you do not need to purchase extra underlayment in that situation.

underlayment for flooring, Word of Mouth Floors Richmond BC Canada

2) Is Moisture a concern?

A function of many types of underlayment is to help prevent moisture from the subfloor (ie: concrete) from coming up into the flooring. A plywood subfloor does not require a vapor barrier, a concrete subfloor does.

Underlayment with vapour barrier built in is literally a barrier against subfloor moisture, therefore protecting the flooring from that moisture. All concrete holds moisture in it, it’s a characteristic of concrete. So flooring manufactures require you install your floating floor with a vapour barrier. The easiest way to do that is to have it included in your underlayment roll.

3 in 1 underlayment for flooring, Word of Mouth Floors Richmond BC Canada

3) Is Sound from your Flooring a concern?

A top feature in quality underlayment is its roll as a sound barrier.   It is used to muffle sounds not only between different levels in the home but also those made from walking on the floor itself.  Sound ratings are given for the level of sound repression you can get in your underlayment. You want to have a material included in your underlayment to help with sound transfer.

The best 3 in 1 underlayments with high STC & IIC sound ratings are frequently used in condominium and apartment construction, where Strata boards often require minimum sound decibel requirements to cut down on sound transmission between floors.

4) Is my Subfloor perfect?

High quality, dense (often 3 in 1) underlayment rolls help provide added support as the flooring expands and shifts during temperature and humidity changes. The thicker or more robust underlayment options help cover deficiencies in the the subfloor. You also need to carefully prepare your subfloor before installation to ensure a successful installation… but higher quality underlayment goes a long way to helping create a successful install. That quality underlayment will ensure your float floats as it should with a secure subfloor combination and help the flooring deal with changes in environment.

5) Flooring Budget

This seems obvious, but you get what you pay for. You can keep pricing of your flooring investment lower with entry level underlayment. If you have a single level ranger style home with plywood subfloor, with little worry about sound transfer, then you can go with a basic 2 in 1 inexpensive underlayment. For piece of mind and higher performance, premium underlayment can cost double, triple or even more than the entry level underlayment. Our best selling is the sound resistant 3 in 1 product. It is still very reasonably priced, but give extra performance vs the entry level 2 in 1 option.

Do I need underlayment for vinyl flooring with attached pad?

First, let's clarify what SPC and WPC vinyl flooring are. SPC stands for stone polymer composite, while WPC stands for wood polymer composite. Both types of vinyl flooring are made with a high-density core layer and a wear layer on top, but SPC is typically more rigid and durable, while WPC is more flexible and softer underfoot.

Now, when it comes to whether or not you need underlayment for SPC or WPC vinyl flooring with an attached pad, the general rule is still that you don't need it. However, there are a few situations where using underlayment may be recommended:

Uneven subfloor: If the subfloor is not level or has any imperfections, using underlayment can help create a smooth and even surface for the vinyl flooring to lay on. This will prevent any bumps or ridges from showing through the flooring and causing damage over time.

Noise reduction: If you want to reduce the sound of footsteps or other noises, using underlayment with sound-dampening properties can help absorb sound and minimize noise transmission.

Moisture barrier: If the subfloor is concrete or prone to moisture, using underlayment with a built-in moisture barrier can help protect the vinyl flooring from any water damage.

Thermal insulation: If you live in a cold climate and want to add extra insulation to your floors, using underlayment with thermal insulation properties can help keep your home warm and energy-efficient.

Cushioning: While SPC and WPC vinyl flooring with attached pads are already designed to provide some cushioning underfoot, using an additional underlayment with cushioning properties can make the floor even more comfortable to walk on.

However, there are also some reasons to be cautious when using underlayment with vinyl flooring. Here are a few potential issues to keep in mind:

Too much cushioning: If you use an underlayment that is too thick or has too much cushioning, it can put too much stress on the joints of the floating floor and cause it to crack or buckle over time. Be sure to follow the manufacturer's recommendations for the thickness of the underlayment.

Compatibility: Not all underlayments are compatible with all types of vinyl flooring. Be sure to check with the manufacturer of the flooring and the underlayment to ensure that they are compatible with each other.

Warranty: Some vinyl flooring manufacturers may require specific underlayment products to be used in order to maintain the warranty. Be sure to check the warranty information before installing an underlayment.

Overall, while underlayment is not always necessary for SPC or WPC vinyl flooring with an attached pad, there are some situations where it can be beneficial. Just be sure to choose an underlayment that is compatible with your flooring and follow the manufacturer's guidelines for installation.

What is the maximum thickness of underlayment I can add for vinyl flooring with attached pad?

When it comes to the maximum thickness of underlayment that can be installed under a 4mm SPC vinyl floor, it's important to follow the manufacturer's recommendations. In general, most manufacturers recommend using an underlayment that is no more than 2mm thick when installing SPC vinyl flooring with a 4mm core.

This is because using an underlayment that is too thick can put stress on the joints of the floating floor and cause it to buckle or warp over time. Additionally, using an underlayment that is too thick can create an uneven surface that may show through the flooring or cause it to wear unevenly.

That being said, it's always a good idea to check with the manufacturer of your SPC vinyl flooring to see what their specific recommendations are for underlayment thickness. They may have specific guidelines or requirements that you need to follow in order to maintain your warranty or ensure the longevity of your flooring.

SPC vinyl flooring with a 4mm core and a 1mm attached pad, can I add more underlayment? How much?

Yes, if you have an SPC vinyl flooring with a 4mm core and a 1mm attached pad, using an underlayment that is no thicker than 1mm is generally recommended. This will ensure that the total thickness of the flooring and underlayment is within the manufacturer's recommended guidelines and prevent any potential issues with the joints or overall performance of the flooring.

However, it's always a good idea to check the manufacturer's specific recommendations for the flooring and underlayment you plan to use, as they may have different requirements or guidelines based on their product specifications. Additionally, using an underlayment may not always be necessary, so it's important to consider your specific installation needs and goals when deciding whether or not to use an underlayment with your SPC vinyl flooring.

Cork Underlayment pros and Cons

Cork underlayment is a popular option for use under vinyl flooring, as it offers a number of benefits. Here are some of the pros and cons of using cork underlayment:


Excellent sound insulation properties, making it a great choice for use in multi-level homes or buildings.

Provides thermal insulation, which can help keep your home more comfortable and reduce energy costs.

Soft and comfortable underfoot, which can make your flooring feel more comfortable and reduce foot fatigue.

Made from sustainable materials, which can be a good choice for environmentally conscious consumers.


May be more expensive than other types of underlayment.

Can be more difficult to install than some other types of underlayment.

Can be susceptible to damage from moisture or mold growth if not installed properly or maintained well.

Cork underlayment is typically available in thicknesses ranging from 1/8 inch to 1/2 inch, with 1/4 inch being a common thickness used under vinyl flooring. It is usually sold in rolls or sheets, and can be easily cut to fit your specific installation needs.

Whether or not cork underlayment is recommended for use under a 4mm SPC core vinyl flooring that already has a 1mm pad attached will depend on the specific recommendations of the flooring and underlayment manufacturers. In general, if you are looking to add extra sound insulation or thermal insulation to your flooring, cork underlayment may be a good choice. However, you should always check the manufacturer's recommendations for both the flooring and underlayment to ensure that using cork underlayment is a suitable option for your installation. It's also important to note that adding additional underlayment to a flooring product that already has a pad attached may not always be necessary or recommended, so it's important to consider your specific needs and goals before making a decision.

Do I need underlayment for vinyl flooring with attached pad if I am concerned about moisture?

If you have concerns about moisture from your concrete subfloor, it's generally recommended to use a moisture barrier or vapor barrier underneath your SPC vinyl flooring, even if the flooring already has a pad attached. A moisture barrier will help to prevent moisture from the subfloor from reaching the flooring, which can cause damage or lead to problems with mold or mildew growth.

There are a variety of different moisture barrier options available, including plastic sheeting or specially designed moisture barrier underlayment products. When selecting a moisture barrier, it's important to choose a product that is specifically designed for use under vinyl flooring and that meets the moisture protection requirements of your specific installation.

In addition to using a moisture barrier, there are other steps you can take to help prevent moisture issues in your flooring, such as ensuring that your concrete subfloor is properly sealed and allowing adequate ventilation and air flow in the room. If you are uncertain about the moisture levels in your subfloor, it may be a good idea to have a professional contractor perform a moisture test before installing your flooring to ensure that the subfloor is adequately prepared for installation.